Those changes, in turn, constantly change the way that Gus Dimitrelos approaches his other job, examining digital information in criminal cases.

He pointed to a 2007 case involving a Mobile man whose laptop computer contained password-protected files with an unusual level of security — comparable to systems meant to protect the government’s top secrets.

Federal prosecutors convicted Michael Ryan South of traveling across state lines to have sex with a child, and he received a life sentence.

He said that it was important to learn the computer’s secrets to identify possible victims and to provide backup evidence in case the conviction ever got overturned.

Dimitrelos used encryption-breaking software — at times harnessing up to 5 computers simultaneously on the project. Each computer had an Intel Core Duo processor, resulting in the equivalent of 10 computers.

The software, Password Recovery Toolkit, was capable of sorting through groups of possible passwords at a rate of 250,000 a second.

The code remains a mystery, but Dimitrelos hasn’t given up hope of ever cracking it. Eventually, he said, advancements in technology should make it a fairly simple task.

“Encryptions that were unbreakable years ago, now we can break them in a matter of minutes,” he said.